In many applications today, tube cameras are used in the environments mentioned above because they are more radiation tolerant compared to cameras that are provided with CCD or CMOS image sensors. It is normally possible to separate any required electronic control units from the radioactive environment and thus avoid or limit some severe effects of the radiation. The conditions of using other types of cameras, and specifically digital cameras, however, are different.
Ionizing radiation affects and finally destroys electronic equipment, specifically low voltage and more compact circuits and circuits with high spatial resolution. The ionizing radiation mainly causes temporary damage, so-called soft errors or single-event damage, and permanent damage, so-called atomic displacement.
Commercially available devices of today suffer from these effects and produce images of continuously deteriorating quality. The cameras and associated control logic will be broken or have a decreased performance level only after a short period of use in the above-described harsh environment. There is still a need for better image quality that can be achieved with digital image sensors and also a need for cameras that will last longer in such environments.